A survey of irrigation water and soil quality that likely impacts paddy rice yields in Kilimanjaro, Tanzania

AbstractIn this study, the impacts of irrigation water quality and soil characteristics on paddy rice yields were investigated. Standard spectroscopy and spectrometry methods were used to analyze irrigation water and irrigated soil samples. The irrigation water had sodium adsorption ratio (SAR) values ranging from 0 to 3. The corresponding electrical conductivity (EC) values were between 0.2 and 0.7 dS/m and accounted for 14% of all samples—posing slight to moderate infiltration problem. Neither Na+ nor Cl− levels were high enough to cause toxicity problems in the irrigation water. For B, 54% of the samples were found to have moderate toxicity whereas ~ 14% of the samples indicated severe B toxicity in the irrigation water. For bicarbonate, about 86 and 14% of the irrigation water indicated slight-to-moderate and severe potential detrimental effect to plant growth, respectively. All trace elements in the irrigation water were too low to cause any harmful effect. Although soil EC, organic carbon (OC), and pH indicated favorable level, there were high standard deviation (SD) values in soil Fe and Zn. The mean value of Fe in soils was 19.8 mg/kg, indicating signs of Fe-deficiency. High SD values were also found in the total N (TN) content of the studied soils. Furthermore, a low soil K content was observed in the analyzed soil samples. Appropriate fertilizer application for improving nutrient deficiencies in the study area is highly recommended. Furthermore, on-farm management practices need to be guided by scientific findings from the present as well as other studies.

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Nutrient Management Programs, Nitrogen Fertilizer Practices, and Groundwater Quality in Nebraska’s Central Platte Valley (U.S.), 1989–1998

The Scientific World JOURNAL ◽

10.1100/tsw.2001.365 ◽

2001 ◽

Vol 1 ◽

pp. 750-757 ◽

Cited By ~ 2

Author(s):

Stan Daberkow ◽

Harold Taylor ◽

Noel Gollehon ◽

Milt Moravek

Keyword(s):

Irrigation Water ◽

Fertilizer Application ◽

Management Program ◽

N Fertilizer ◽

N Availability ◽

Modest Improvement ◽

Total N ◽

Drinking Water Standard ◽

Irrigation Water Use ◽

Farmer Behavior

Given the societal concern about groundwater pollution from agricultural sources, public programs have been proposed or implemented to change farmer behavior with respect to nutrient use and management. However, few of these programs designed to change farmer behavior have been evaluated due to the lack of detailed data over an appropriate time frame. The Central Platte Natural Resources District (CPNRD) in Nebraska has identified an intensively cultivated, irrigated area with average groundwater nitrate-nitrogen (N) levels about double the EPA’s safe drinking water standard. The CPNRD implemented a joint education and regulatory N management program in the mid-1980s to reduce groundwater N. This analysis reports N use and management, yield, and groundwater nitrate trends in the CPNRD for nearly 3000 continuous-corn fields from 1989 to 1998, where producers faced limits on the timing of N fertilizer application but no limits on amounts. Groundwater nitrate levels showed modest improvement over the 10 years of this analysis, falling from the 1989–1993 average of 18.9 to 18.1 mg/l during 1994–1998. The availability of N in excess of crop needs was clearly documented by the CPNRD data and was related to optimistic yield goals, irrigation water use above expected levels, and lack of adherence to commercial fertilizer application guidelines. Over the 10-year period of this analysis, producers reported harvesting an annual average of 9729 kg/ha, 1569 kg/ha (14%) below the average yield goal. During 1989�1998, producers reported annually applying an average of 162.5 kg/ha of commercial N fertilizer, 15.7 kg/ha (10%) above the guideline level. Including the N contribution from irrigation water, the potential N contribution to the environment (total N available less estimated crop use) was estimated at 71.7 kg/ha. This is an estimate of the nitrates available for denitrification, volatilization, runoff, future soil N, and leaching to groundwater. On average, between 1989–1993 and 1994–1998, producers more closely followed CPNRD N fertilizer recommendations and increased their use of postemerge N applications � an indication of improved synchrony between N availability and crop uptake.

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Carbon footprint of crop production in China: an analysis of National Statistics data

The Journal of Agricultural Science ◽

10.1017/s0021859614000665 ◽

2014 ◽

Vol 153 (3) ◽

pp. 422-431 ◽

Cited By ~ 48

Author(s):

K. CHENG ◽

M. YAN ◽

D. NAYAK ◽

G. X. PAN ◽

P. SMITH ◽

...

Keyword(s):

Carbon Footprint ◽

Crop Production ◽

Management Practices ◽

Fertilizer Application ◽

N Fertilization ◽

Paddy Rice ◽

N Fertilizer ◽

Carbon Equivalent ◽

Ghg Mitigation ◽

Application Rates

SUMMARYAssessing carbon footprint (CF) of crop production in a whole crop life-cycle could provide insights into the contribution of crop production to climate change and help to identify possible greenhouse gas (GHG) mitigation options. In the current study, data for the major crops of China were collected from the national statistical archive on cultivation area, yield, application rates of fertilizer, pesticide, diesel, plastic film, irrigated water, etc. The CF of direct and indirect carbon emissions associated with or caused by these agricultural inputs was quantified with published emission factors. In general, paddy rice, wheat, maize and soybean of China had mean CFs of 2472, 794, 781 and 222 kg carbon equivalent (CE)/ha, and 0·37, 0·14, 0·12 and 0·10 kg CE/kg product, respectively. For dry crops (i.e. those grown without flooding the fields: wheat, maize and soybean), 0·78 of the total CFs was contributed by nitrogen (N) fertilizer use, including both direct soil nitrous oxide (N2O) emission and indirect emissions from N fertilizer manufacture. Meanwhile, direct methane (CH4) emissions contributed 0·69 on average to the total CFs of flooded paddy rice. Moreover, the difference in N fertilizer application rates explained 0·86–0·93 of the provincial variations of dry crop CFs while that in CH4 emissions could explain 0·85 of the provincial variation of paddy rice CFs. When a 30% reduction in N fertilization was considered, a potential reduction in GHGs of 60 megatonne (Mt) carbon dioxide equivalent from production of these crops was projected. The current work highlights opportunities to gain GHG emission reduction in production of crops associated with good management practices in China.

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Impact of Nitrogen Management Practices on Total Nitrogen in the Fruits of High Productive Hamlin Orange Trees

HortScience ◽

10.21273/hortsci.33.3.498e ◽

1998 ◽

Vol 33 (3) ◽

pp. 498e-498

Author(s):

S. Paramasivam ◽

A.K. Alva

Keyword(s):

Crop Production ◽

Management Practices ◽

Fine Sand ◽

Fruit Production ◽

Perennial Crop ◽

Total N ◽

N Removal ◽

Leaf N Concentration ◽

N Rates ◽

Orange Trees

For perennial crop production conditions, major portion of nutrient removal from the soil-tree system is that in harvested fruits. Nitrogen in the fruits was calculated for 22-year-old `Hamlin' orange (Citrus sinensis) trees on Cleopatra mandarin (Citrus reticulata) rootstock, grown in a Tavares fine sand (hyperthermic, uncoated, Typic Quartzipsamments) that received various N rates (112, 168, 224, and 280 kg N/ha per year) as either i) broadcast of dry granular form (DGF; four applications/year), or ii) fertigation (FRT; 15 applications/year). Total N in the fruits (mean across 4 years) varied from 82 to 110 and 89 to 111 kg N/ha per year for the DGF and FRT sources, respectively. Proportion of N in the fruits in relation to N applied decreased from 74% to 39% for the DGF and from 80% to 40% for the FRT treatments. High percentage of N removal in the fruits in relation to total N applied at low N rates indicate that trees may be depleting the tree reserve for maintaining fruit production. This was evident, to some extent, by the low leaf N concentration at the low N treatments. Furthermore, canopy density was also lower in the low N trees compared to those that received higher N rates.

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Residues and Persistence of Glyphosate in Irrigation Water

Weed Science ◽

10.1017/s0043174500065395 ◽

1976 ◽

Vol 24 (1) ◽

pp. 47-50 ◽

Cited By ~ 12

Author(s):

R. D. Comes ◽

V. F. Bruns ◽

A. D. Kelley

Keyword(s):

Irrigation Water ◽

Soil Samples ◽

Single Site ◽

Application Site ◽

Canal Water ◽

Aminomethylphosphonic Acid ◽

Dry Soil

Neither glyphosate [N-(phosphonomethyl)glycine] nor the soil metabolite aminomethylphosphonic acid were detected in the first flow of water through two canals following application of glyphosate at 5.6 kg/ha to ditchbanks when the canals were dry. Soil samples collected the day before canals were filled (about 23 weeks after treatment) contained about 0.35 ppm glyphosate and 0.78 ppm aminomethylphosphonic acid in the 0 to 10-cm layer. When glyphosate was metered into the water at a rate calculated to provide 150 ppb in the canal water at a single site on two flowing canals, about 70% of the glyphosate was accounted for 1.6 km downstream from the application site. Thereafter, the rate of disappearance diminished, and about 58% of the applied glyphosate was present at the end of the canals 8 or 14.4 km downstream from the introduction sites.

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Effect of Soil Management on Erosion in Mountain Vineyards (N-W Italy)

Sustainability ◽

10.3390/su13041991 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1991

Author(s):

Silvia Stanchi ◽

Odoardo Zecca ◽

Csilla Hudek ◽

Emanuele Pintaldi ◽

Davide Viglietti ◽

...

Keyword(s):

Soil Erosion ◽

Management Practices ◽

Soil Management ◽

Buffer Strips ◽

Total N ◽

Organic C ◽

Erosion Rates ◽

Soil Ecosystem Services ◽

Erosion Mitigation ◽

Management Approaches

We studied the effects of three soil management approaches (permanent grassing, chemical weeding, and buffer strips), and the additional impact of tractor passage on soil erosion in a sloping vineyard located in the inner part of Aosta Valley (N-W Italian Alps). The vineyard rows were equipped with a sediment collection system with channels and barrel tanks. A total of 12 events with sediment production were observed across 6 years, and the collected sediments were weighted and analyzed. Average erosion rates ranged from negligible (mainly in grassed rows) to 1.1 t ha−1 per event (after weeding). The most erosive event occurred in July 2015, with a total rainfall of 32.2 mm, of which 20.1 were recorded in 1 h. Despite the limited number of erosive events observed, and the low measured erosion rates, permanent grassing reduced soil erosion considerably with respect to weeding; buffering had a comparable effect to grassing. The tractor passage, independent of the soil management approaches adopted, visibly accelerated the erosion process. The collected sediments were highly enriched in organic C, total N, and fine size fractions, indicating a potential loss of fertility over time. Despite the measured erosion rates being low over the experiment’s duration, more severe events are well documented in the recent past, and the number of intense storms is likely to increase due to climate change. Thus, the potential effects of erosion in the medium and long term need to be limited to a minimum rate of soil loss. Our experiment helped to compare soil losses by erosion under different soil management practices, including permanent grassing, i.e., a nature-based erosion mitigation measure. The results of the research can provide useful indications for planners and practitioners in similar regions, for sustainable, cross-sectoral soil management, and the enhancement of soil ecosystem services.

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Innovative Extension Methods in the U.S. to Promote Irrigation Water Management

Transactions of the ASABE ◽

10.13031/trans.13929 ◽

2020 ◽

Vol 63 (5) ◽

pp. 1549-1558

Author(s):

Daran R. Rudnick ◽

Matt Stockton ◽

Saleh Taghvaeian ◽

Jason Warren ◽

Michael D. Dukes ◽

...

Keyword(s):

Water Management ◽

Experiential Learning ◽

Best Management Practices ◽

Irrigation Water ◽

Management Practices ◽

New Technology ◽

List Type ◽

Extension Programs ◽

Irrigation Water Management ◽

Primary Means

HIGHLIGHTSUniversity extension has been playing a larger role, serving a larger number of irrigated farms.Extension programs in irrigation water management (IWM) have been transitioning away from lectures and field tours as the primary means of knowledge transfer.New IWM programs focus on experiential learning, development of practitioner networks, and industry participation.Abstract. Promotion and adoption of irrigation water management (IWM) technology, tools, and best management practices are important as water availability concerns are addressed. Traditional extension programs have relied on lecture presentations, field tours, fact sheets, and on-station demonstrations to promote IWM practices and tools. However, these platforms tend not to provide the experience and opportunity for growers to identify and become comfortable with innovative solutions, such as new technology. To address these challenges and to appeal to an ever-changing client base, innovative and locally relevant extension and outreach programs have been devised to engage and educate growers. This article describes some of these programs that extend beyond previous traditional programs to connect growers with IWM. Keywords: Demonstrations, Experiential learning, Grower competition, Outreach, Practitioner networks.

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N Management of European Grasslands: Can the Exchange of Gaseous N Species Be Influenced at the Operational Level?

The Scientific World JOURNAL ◽

10.1100/tsw.2001.373 ◽

2001 ◽

Vol 1 ◽

pp. 652-657 ◽

Cited By ~ 1

Author(s):

P. Calanca ◽

A. Neftel ◽

J. Fuhrer

Keyword(s):

Late Summer ◽

Fertilizer Application ◽

Effective Control ◽

Management Options ◽

Total N ◽

Model Calculations ◽

Weather Forecasts ◽

Grassland Ecosystems ◽

Order Of Magnitude ◽

N Management

Grassland ecosystems can be regarded as biochemical reactors in which large amounts of organic nitrogen (N) are converted into inorganic N, and vice versa. If managed in a sustainable manner, grasslands should operate in a quasi steady state, characterized by an almost perfect balance between total N input and output. As a consequence, the exchange of gaseous N species (NH3, NO, NO2, N2O, and N2) between grasslands and the atmosphere is very small compared to the total N turnover. In this study, the effects of two management options (mowing and fertilization) on production and emission of nitrous oxide (N2O) from a grass/clover crop were examined on the basis of observations and model results referring to an experiment carried out on the Swiss Plateau in late summer of 2000. It was found that production and emission of N2O induced by mowing were of the same order of magnitude as those brought about by fertilization, suggesting a possible transfer of N from clover to the soil after defoliation. Emissions were strongly modulated by precipitation on time scales ranging from 1 day to 1 week. This indicates that effective control of N2O emissions through management on a day-to-day basis requires reliable medium-range weather forecasts. Model calculations were not able to reproduce essential characteristics of the emissions. The model slightly overestimated the background emissions, but severely underestimated the emission peaks following fertilizer application, and largely failed to reproduce emission induced by mowing. Shortfalls in the model used for this study were found in relation to the description of soil-water fluxes, soil organic matter, and the physiology of clover.

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RESTORING PRODUCTIVITY TO AN ARTIFICIALLY ERODED DARK BROWN CHERNOZEMIC SOIL UNDER DRYLAND CONDITIONS

Canadian Journal of Soil Science ◽

10.4141/cjss86-029 ◽

1986 ◽

Vol 66 (2) ◽

pp. 273-285 ◽

Cited By ~ 18

Author(s):

J. F. DORMAAR ◽

C. W. LINDWALL ◽

G. C. KOZUB

Keyword(s):

Organic Matter ◽

Soil Erosion ◽

Green Manure ◽

Soil Structure ◽

Management Practices ◽

Fertilizer Application ◽

Sweet Clover ◽

Yield Losses ◽

Critical Factors ◽

Structure Characteristics

A field was artificially eroded by levelling in 1957 and then continuously cropped to barley for 7 yr. Subsequently, a wheat-fallow experiment was conducted from 1965 to 1979 to determine the effects of four fertilizer treatments and green manure (yellow sweet clover) on restoring the productivity to soil that had been "eroded" to various depths. After 22 yr and 14 crops, the productivity of the land from which soil was removed has been improved but not fully restored. Although green manuring with yellow sweet clover improved soil structure, wheat yields were not improved because of competition for soil moisture and poorer in-crop weed control in this part of the rotation. The addition of 45 kg N plus 90 kg P2O5 per hectare in each crop year to sites from which 8–10, 10–20, or 46 + cm of soil had been removed resulted in yield increases of 18, 46, and 70%, respectively, over the unfertilized check of each treatment; the average yields were 104, 91, and 70%, respectively, of the undisturbed, unfertilized (check) treatment. On "erosion" treatments where only 8–10 cm of soil were removed, 45 kg N plus 22 kg P2O5 per hectare were sufficient to restore the productivity. Precipitation apparently had a greater effect than fertilizer application on wheat yields. The loss of organic matter and associated soil structure characteristics seemed to be critical factors contributing to yield losses associated with soil erosion. These results show that it is more practical to use management practices that prevent soil erosion than to adopt the practices required to restore eroded soil. Key words: Soil erosion, topsoil loss, water-stable aggregates, soil organic matter, green manure, precipitation

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Determining Optimum Calcium and Magnesium Sources and Rates for Home Gardeners Growing Vegetables in Potting Media Using Alkaline Irrigation Water

HortTechnology ◽

10.21273/horttech03316-16 ◽

2017 ◽

Vol 27 (1) ◽

pp. 108-113

Author(s):

Sarah B. Everhart ◽

Kathryn K. Fontenot ◽

Edward W. Bush ◽

Charles E. Johnson

Keyword(s):

Brassica Oleracea ◽

Irrigation Water ◽

Fertilizer Application ◽

Home Garden ◽

Vegetable Production ◽

Lime Treatment ◽

Greenhouse Production ◽

Dolomitic Lime ◽

High Tunnel ◽

Industry Standard

Home gardeners living in areas with alkaline water sources do not have easy or economically affordable means of acidifying irrigation water for vegetable production. One solution for achieving optimal vegetable yields using alkaline irrigation water is to grow the vegetables in a modified medium. To date, no medium on the retail market suits such growing needs. Therefore, medium recipes with varied levels (0, 4, or 8 lb/yard3) and sources of calcium [dolomitic lime, calcium sulfate (CaSO4)] and magnesium [dolomitic lime, magnesium sulfate (MgSO4)] were tested using an alkaline irrigation on ‘Oakleaf’ lettuce (Lactuca sativa), ‘Earliana’ and ‘Salad Delight’ cabbage (Brassica oleracea var. capitata), and ‘Snow Crown’ cauliflower (Brassica oleracea var. botrytis) crops. Additionally, crops were grown in two environments, under a high tunnel and on a nursery yard. High tunnel and nursery yard sites were used to test media performances in the presence of, and eliminating, rainwater to simulate container-grown vegetables growing in both a home garden situation and a commercial greenhouse production situation. The base mix of all media treatments in the study was 80 bark : 20 peat and fertilized with 12 lb/yard3 slow-release fertilizer at a rate of 1.8 lb/yard3 nitrogen (N), 0.5 lb/yard3 phosphorus (P), and 1 lb/yard3 potassium (K). This initial fertilizer application was incorporated to each medium before filling containers. Four treatments were tested against a commercially available medium, industry standard (IS) treatment (a commercially available bagged medium), and a control medium [treatment C (no supplemental calcium or magnesium fertilizer)] by supplementing the base mix with the following fertilizer levels: 4 lb/yard3 each of CaSO4 and MgSO4 (treatment 1); 4 lb/yard3 dolomitic lime (treatment 2); 4 lb/yard3 each of dolomitic lime, CaSO4, and MgSO4 (treatment 3); 8 lb/yard3 dolomitic lime (treatment 4). Media treatments 1 through 4 outperformed the IS and C media treatments in nearly all crops. All crops grown on the nursery yard, and cabbage grown under the high tunnel, had greater yields when grown in medium treatment 3, compared with the IS and C media treatments (P ≤ 0.05). All crops grown in medium treatment 2 on the nursery yard produced greater yields than the IS and C media treatments (P ≤ 0.05).

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Deep subsoiling of a subsurface-compacted typical hapludult under citrus orchard

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832013000400008 ◽

2013 ◽

Vol 37 (4) ◽

pp. 911-919 ◽

Cited By ~ 7

Author(s):

João Carlos Medeiros ◽

Getulio Coutinho Figueiredo ◽

Álvaro Luiz Mafra ◽

Jaqueline Dalla Rosa ◽

Sung Won Yoon

Keyword(s):

Hydraulic Conductivity ◽

Management Practices ◽

Soil Management ◽

Penetration Resistance ◽

Soil Bulk Density ◽

Soil Samples ◽

Fruit Yield ◽

Root Depth ◽

Citrus Orchard ◽

Unsaturated Hydraulic Conductivity

Soil management practices which increase the root depth penetration of citrus are important to the longevity and yield maintenance of this plant, especially in regions where long periods of drought are common, even in soil conventionally subsoiled to a depth of 30-40 cm, when the orchard was first established. The objective of this study was to evaluate the efficiency of subsoiling on the physical and hydric properties of a Typical Hapludult and fruit yield in a 14-year-old citrus orchard located in Piracicaba, SP. The treatments consisted of: no-subsoiling (with no tilling of the soil after the orchard was planted); subsoiling on one side of the plant lines (SUB. 1); and subsoiling on both sides of the plant lines (SUB. 2). The subsoiling treatments were carried out 1.5 m from the plant lines and to a depth of 0.8 m. Soil samples were taken 120 days after this operation, at four depths, in order to determine physical and hydric properties. Fruit yield was evaluated 150 days after subsoiling. Subsoiling between the plant lines of an old established citrus orchard alters the physical and hydric properties of the soil, which is reflected in increased soil macroporosity and unsaturated hydraulic conductivity, and reduced soil bulk density, critical degree-of-compactness and penetration resistance. The improvements in the physical and hydric properties of the soil were related to an increase in fruit number and orchard yield.

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